Vacuum pump



Nov. 3, 1931. J. F. METTEN 1,329,908

VACUUM PUMP Filed March 19, 1930 2 Sheets-Sheet 1 INVENTOR.

? Jo/7N PM: 772716 J. F. METTEN VACUUM PUMP Filed March 19, 1950 2 Sheets-Sheet 2 /JTTORNEYS.

f fmosphe'ric' pressure at sea level and dischargngi thefair or gases removed ator above at- IIl OSPlIGIfICZPIBSSIlIQ. "Pump's'of this charac- Patented Nov. 3; 1931 I Jonnr. Em a, or rHILADELP 'IA, PENNSYLVANIA 5' [This invention relates to' rotary vacuum pumps for withdrawing airanfd other" gases from spaces that aref'required to be main" mined; at ,pr'essures considerably below I at- A ten have numerousapplications in connection w 'p es a d umping equipment I in steam'stations manufacturing plants, etc.

The early vacuum pumps of reciprocating fand rotary displacement types which have been used are beingdiscarded in favor of "vacuum" pumps operating on'the 1' et principle" '15 andusing the kinetic energy of steam and ,water as the'pumping medium by: employing the entraining and compression principle of high velocity jets. In manyprocesses the use "ofjsteam is objectionable due toits heating, 2 action, and where it is, used for higher, vacuum itis' necessaryvtocarry out the Work of Withdrawal and compression :toatmospheric pressure in anumber of stages and to provide coolers between eachstagefto condense the I steam used in the preceding stage, to reduce the temperature and corresponding volume of the airor other gases moved,

In many caseswateryjet vacuum pumps are desirable on account of the" absence of 2 o heating action and test duejto the fact that single stage pumps ofthis type are capable of providing comparatively high vacuum.

The water jet ejector,';however, requiresa separate pump or. other means for supplying pressure "water, to the jet," and hence the 7 combined eificiency islow ow'ing to the combined hydraulic losses in'the pump and ej ec- I Itis therefore the object of my invention to produce a novel fvacuum'pump wherein the V us'e'ofsteam with its'co nsemuent heating is entirely eliminated and wherein no auxiliary "pression s'neededfl *Itis a further object pump to propelfthe -'vvater or} to create comof'my invention to provide a rotary vacuum'pump which is capable of producing a relatively high vacuum Tothe aboveends my invention consists of iciipiles unde v I vAouuM star; i p f ma filed MarcnQ19'j1930 fsferiai in). 436,922.

' head, a plurality of suction nozzles I carried thereby, {a wateryjacket surrounding said headymeans for actuating said head, means f for preventing the rotation of the Waterjsurrou'n-ding said'head, and connections leading from'said nozzles to the point where the vacuum is to be created.

My invention still further'consists in various other novel featuresof construction and assembly all as hereinafter described and claimed V For, the purpose o t-illustrating my inVen-' rjtionhI have shown in the accompanying drawlngs one formthereof which is at pies e'en ent preferred by me, since thesame has found in practice to give satisfactory and In the V accompanying drawings Figure "1 represents a yiew, partly in secv tion and-partly in elevation, of a novel vacu- 'um pump embodying my invention.'

Figure 2 represents a section on line 2-2 :of Figure 1 V Figure 3 represents a section on line 3 -3 "of Figure 1. r

' Figures 4', 5 andfi represent diagrammatic sectional'views illustratingsome of the prin- I rlying, my invention and the mode ofoperation,

Figure 7 represents a longitudinal sectional view of aconventional' water et pump which may be helpful in describing and explaining the present invention.

Referringto the drawings in which l1ke reference characters indicate likeparts, '1 designatesia vacuum pump embodying my invention andcomprising the separating llqllld tank or reservoir? to which is connected the runnerchamber or jacket 3 by'means ofthe upper and lower portst'and 5. 6 designates stationary f pipe leading from the point where the vacuum-is to be created and extending downwardly into the chamber orjacket 3 where-its lower end is engaged by the extension 7 of the rotary. head or runner 8 n which'is carried by the shaft 9 which is and it communicateswith the'lower portion of the suctionfpipe 6 as will be understood i ber 3and the'tank-2to the le'yel'l8; 19 desjournalled or provided with aligning bearings at 10and driven by any'suitable source v0i power'as a driving" motor or turbine 11.;

water jetpump shown infFig. 7 wherein the The rotary head or runner 8 is provided with the nozzles 12 and theifan blades orvanes 13 from Figures 1 and 3. 14 and 15 designate annular passages corresponding to the '.circu'-v lar path sweptby'-the nozzles 12. V The passages let and 15 a-re'provided' with the fixed blades or bafliesllti and lflwhich serve to.

prevent the rotation of the liquid in [which the rotary headfor' runner is immersed' which as willbe seen trom Figure' 1,"fills? the cham ig nates a bottom bearing'plate which is below v rand-out of contact with the heaclor grunner 8 and which carries the lower fixed blades 16 while 20 designates; a stufling-boxqfor the upper casing. which encloses [the lower porition-ogt the pipe 6and which carries the upper fixed ,blades 17 The runner chamber is preferably made in two upper andlower .sectionswhich are joined together at21, said uppernand lower sections being joined or se cured tothetank 2 at 22, inorder to facilitate *1 go manuf acture and assembly. The nozzles '12 are ellipticalin cross sectiontsee Figs. -andhave the r ma or .ax1s1ncl1nedto the planeiofrotation gofthe runner 8:] When l the, head or runner 8 is ,revolved the angle 35 of the nozzlesel2 servestoimpart toothe surrounding, liquid;a relatively.- slow motion parallel to the Q axis .of rotation as-indicated by the arrows23inliig. 4 ,the-objectjof this being to prevent-interference eithe paths of the different nozzles 12 with respect to "the vliquid. While in thegdrawings I have shown only four nozzles-12. it is tobeunderstood that a greater or less number of nozzlescan andsllction piped; 'This action is similar the water or otherllquid n nearlystatlonary be used depending on the dutyx r -equired.

Th'e lfio-w -of liquid relativeoto' the rotating -nozzles 12, results, in the continuous with -dra wal of the air or gas from the runner 8 in principle to that of theconventional water jet pump, illustrated in Fig. '7, exceptthat and the eduction nozzles are moving at a high speed relative-to-the liquidinstead of the liquid moving at a high speed relative to said nozzles. There is an important'ad .vantage obtainedin this transposition for the reason that thefiow et -gases, on account of ;their--1ow density, can be inducedat high speeds with, small] differences in; pressure. Consequently the moving nozzles 12, forming gaspassages can be 'made of acontour calculated to reduce-resistance due tomotion'of said nozzlesthrough the liquid to minimum, and; also 'to' permit the with'drawal or entraininent of therenio'ved air or gas to take place between two highvelooity surfaces of the liquid relative to the nozzles instead of between the high velocity surfaces of the liquid and the stationary metal wall of the discharge tube in 'the conventionalform of liquid jet is moving at high velocity and the eduction passage walls "areznecessarily sta 'tionary. Referring to- Figure 6, it will be understood that when the nozzles '12 are .m'oved through a liquidfw'hich is stationary -lent' to therate :of acceleration of water particles due to o the iforce "of gravity and is therefore independent of the, yelocity of the moving. nozzles. i Consequently, if thevelocity ofthe nozzles 12 through the liquid is great enough with, respect to they-constant 'velocityof inflow referred to, there will be a vacuum, cavity 26 of wedge section formed back ofeach nozzle, the length of whichwill increase in proportion te the velocity "of the nozzlesrelative to the constant velocity of inflow; The inner surfacesof this vacuum space act as 'entraining surfaces and the. air

or gas is compressed to delivery pressure at the apex and passes upward with the vertical movementofzthe liquid in a spiral of small bubbles corresponding to thehelical paths of the nozzles. This is due totheang'le ot'the nozzles 12 and the translatory: motion impartedt.othe liquid in which the runneror head is immersed. These bubbles separate out of the liquid and pass out. through the outlet 24in topot separating tank 2.1; 1

Referringto Figure 5 it will be seen that if the speed of nozzles 12Iis great enough to resultin-the length of vacuum .cavityfl26, greater than the, distance ,(Rlbetween .a-nozzle 12 andthe juxtaposedgu'ide' blades, measured on the axisofsaid nozzle, a change in the-pumping action takes place in, that the final compression ofthe air or gas withdrawn takes place afterthe apex of the vacuum cavity (S) ,[haspassed the ends of said guide blades,as a result otthe verticalfiow of the liquid in which thenozzles rotate. Where speeds can be adopted--permitting this operating condition being 7 obtained, the with-' drawal capacity will be increased, since,.instead of the volumetric capac tybeing dependent principally upon entra nment, it

would approach the volume of liquidswept through by the cross sectional, area of said nozzlesinja givenunit'oftin c.

In Fig. Z I have shown a conventional water jet pump in which water isforced under pressureat theinlet end .27 whichjleads through the reduced nozzle. 28 into the chamber 29. The chamber 29 is provided with a suction pipe 30 leading to the point wherefla vacuum is'tobe created. Asthe water passes through the discharge end 31, the air in the chamber 29 is entrained "and sucked with the water and discharged. The reduced pres-= sure in the chamber29 causes the airyor other gas to flow thereintoflthrough thesuction pipe s; '30 which air is again entrained with the mov- 'ing'jet of water i a' plurality of nozzles which move with re-,

7 spect to a relatively stationary liquid instead the nozzle 31. 1 1

and is' discharged through My invention reverses the process to obtain the advantages above set forth by using of'forming a jet of-water through the fixed discharge nozzle '31, the inner walls of which arest'ationary. Themovement of mynovel wedge shapedor con cal nozzles creates avacuum which sucksi theair fromthe runneror headand'the suction pipe 6. I- am aware that the'invention may be em- I "bodied in other specific forms without departingffrom the" spirit or essential attributes thereof, and I therefore-desire the present embodiment to be considered in all respects as illustrative and notrestrictive, reference being had to the appended claims rather than to the foregoing description to indicate the scope of the invention.

Having thus described my invention what I clann is new and desire to secure by Letters Patent, is

1. A rotary vacuum pump comprising a r 7 suctionpipe, a runner casing, elliptical eduction nozzles immersed in a liquid, and comf municating with'said suction pipe, means for revolving said nozzles in a circular path insaid-liquid at an angle" to their plane of rotation toproduce' suction at the outer ends of said nozzles, and means for separating the su'cke'd gas from said liquid.

2. A rotary vacuum pump comprising a suction pipe, a sectional runner casing, a submerged rotating hollow runner communicating with said suction pipe, elliptical eduction nozzles carried by and communicating with i said runner, said eductionnozzles being indined at an angleto'the1r plane of rotation and provided with terminal openings for discharglngthe a1r sucked from said suction 1 pipe by the rotation of said nozzles, and upper and lower fixed blades'in the upper and lower sections of said runner casing. 1 p

3. A vacuum pump comprising a suction .pipe, a submerged rotating element communicating with said suction pipe and provided with elliptical nozzles having their major axes inclined to their plane of rotation, said nozzles being provided with peripheral discharge outlets so arranged that the movement 7 of said nozzles relative to the surrounding liquid produces a continuous suction at said outlets, to entrain'thecontents of said suction pipe; f V

4. In a vacuum pump, a separating tank adapted to contain a liquid, a runner casing connected at its upper and lower portions to and communicating with said tank, the latter having? ani outlet at the top thereof, aligning bearings 'iir'said casing, a shaft :mountedin sai-dbearings, a rotary element fast on the .loweriend of sai'd shaft,- fixed blades above andbelow said rotary elementfor'preventing 1 rotation of the liquid in which 'said'rotaryeld' ment' is "immersed, and a" stationary sucti pipe having its lower portionenclosing'the v of said shaft and'opening into lower portion said; 'rotary element;

" "5*. In a vacuum pump, a separating tank adapted to contain a liquid, a runner casing connectedat its upper and lower portions to and communicating with said tank, latter having an outlet'at the' top thereof, ahgning hearings in said casing, ashaftmounted iin sa'idbearings, a rotary element fast on the lower 'end of" said shaft-,fixed blades above and below-said rotary element for preventing tio f the liquidiin which said rotary element is immersed, {and a stationary suction pipe having its "lOWGIfPOIlllOIl enclosing the lower portion of "said shaft and opening into said rotary element,- the bottom of said runi 'ner' casing being detachable from the'upper portion thereof and from the bottom of said tank's- I j 6.1'In a vacuum pump," a separating tank adapted to contain aliquid, a runner casing A composed of upper and lower sections connected at its upper and lower portlons to'a-nd communicating with said tank, the latter having an outlet at the top'thereof, aligning having its lower portionenclosing the lowerportionof; said shaft and opening into said rotary element, and means for actuating said rotaryelement and itsshaft.

7 In a vacuum'pump, a separating tank adapted to contain a liquid, a runner casing composed of upper and lower sections con- .nectedat its upper andlower portions to and communicating with said tank, the latter,

having an outlet at the top thereof, aligning bearings in said casing, ashaft mounted in said bearings, a rotary element fast on the lower end of said shaft, fixed bladesin said upperand lower casing sections above and below said rotary element for preventing rotation of the liquid in which said rotary element is immersed, a stationary suction pipe having its lower portion enclosing the lower portion of said shaft and opening into said rotary element, and means for actuating said rotary element and its shaft, the bottom c section of said runner easing beingdetachable from the upper section thereof and from the bottom of said tank.

i runner oas1ng,sa1 d1l0wer sectlon being re- 14 I I q 71,829,908 Q 8. IA rotary ivacuuniprunp com prising'; a V "tank,ia runnerfcasingTcommunieatlng therewithand having mounted therein an edue tion-nozzle secured to 'a" vertically positioned shaft rotatablymonnted in said runner'eas -r -ing,- said nozzle-coacting with upper and lowerjfixed blades for'prev'enting rotation "fof liquid; and a stationary suction pipe p,ar--

V, tiallyenelosing said shaft andghaving an.

-opening"communicating,with said eduction nozzle, the lowe'r'portion of said'runner cas ing beingdetachable and carrying said lower 7' 9 A rotary. vacuum pumpcomprisinga tank, a' runner CflSlIlgCOHlIIlLlDICfltlIIg therezwi'thandhaving mounted therein a plurality 'of elliptically shaped: eduction nozz leslm- 'inersed in aliquid contained insaidtanl: and runner ciasing a shaft' carrying-saidieduetion 1 nozzles, thev maj or, axes offl'said nozzles being i arranged. at wan'a'ngle-to the plane of rotation then'eof to impart fa translatory motion to 1 the liquid parallel tothe'aXis-of rotation of saidnozzles, a stationary suction pipe hav-r ing; its lowerportion, enclosing the lower portion of said shaft and communicating with saideduction nozzles, and-a plurality of upper and lower fixed blades coacting with "said nozzles and mounted in said runner casing for preventing: the rotation of liquid therein. v1

' 10.,111' a device of the character stated, a tank, as'ectional runner casinghavin-g its upvper and lower portions communicating with said'tan-k, ajverti'callydisposed shaft in said runner casing, a submerged-rotary element I secured-to thei lower end of said shaft and v 'having elliptical nozzles; having their major axes inclined to'their-plane of rotation, a suet10n pipe surrounding sa d- "s'haft' and com- ;inunioating at its lowerend with'sa'id rotary r V -element',1fixedblades abovesaid rotary element in' the upper, section of Isaidsect'ional runner. cas ng, and fixed 1 blades .loeiowv said rotary element in lower section of sald movable from said upper section and said tank; s 

